WRC's ban on run-flat tyre foam forces a search for new solutions

June 3, 2007 The success of tyre mousse, a special compound that expands to replace the air in a punctured tyre, has meant that over the last 20 years, flat tyres have ceased to be a factor in World Rally Championship races. The high-tech foam inserts have been so effective that many drivers don't even notice they're running on punctured tyres, and it's not uncommon for race wins and best times to be set after the system is deployed. With new cost-saving FIM regulations being introduced to ban tyre mousse from the 2008 WRC season onwards, teams are searching for ways to minimize the risk and repercussions of the dreaded tyre puncture, which not only knocks cars out of race contention, but can cost upwards of $10,000 in recovery and associated damage costs. One such mitigation strategy is to closely monitor tyre pressure and temperature through a race by using sophisticated sensor systems to detect small leaks and enable the drivers to compensate for them.

Twenty years on from the introduction of mousse-equipped tyres in the WRC, the technology that allows drivers to continue to the end of the stage is to be banned for 2008. However, a robust solution, providing an early warning to drivers of any pressure loss to allow them to preserve the tyre at the earliest opportunity will be available from leading harsh environment tyre pressure monitoring developer BERU F1 Systems.

"The mousse ban means drivers need reliable information about tyre condition and performance to prevent damage to the car," says BERU F1 Systems' managing director John Bailey. "Digi Tyre could give them warning about potential safety issues or whether changing the wheel is the best solution."

The Digi Tyre system is proven in harsh environments including Rally Raid, Le Mans and F1. Lightweight wheel electronics, weighing a mere 35g mount securely to the wheel and transmit to digital antennae which feeds information to an ECU and the in-vehicle display. Actual pressure and temperature can be seen in real time, offering the accurate data to driver or co-driver.

The system is flexible enough to automatically identify wheel changes without software reprogramming, meaning even a wheel change mid-stage poses no concerns to the system. In the service park, wireless handheld devices offer the opportunity for mechanics and engineers to assess temperature and pressure without physically touching the car.

The system will also offer benefits in testing. "The safety and performance advantages of tyre monitoring together with optimization of tyre wear and vehicle handling characteristics will assist engineers to maximise even a limited test schedule," concludes Bailey.

BERU F1 Systems current activity in WRC includes the manufacture of wiring looms for WRC and S2000 cars together with composite components, torque measurement systems, loadcells and the range of Autosport connectors.